Neuroimaging features of spontaneous intracranial hypotension

We reviewed the cranial MRI and radionuclide cisternograms of four adults w ith postural headache indicating spontaneous intracranial hypotension (SIH) . All four underwent clinical and radiological follow-up. MRI showed diffus e, thin meningeal enhancement; bilateral subdural fluid collections; and mo rphological abnormalities secondary to "sagging" of the brain. Radionuclide cisternography revealed direct or indirect signs of leakage of cerebrospin al fluid (CSF) along the spinal axis, and the symptoms resolved after the l eak treated by epidural injection of blood at a level indicated by the cist ernogram. The diffuse meningeal enhancement decreased but persisted on foll owup MRI, although the patients were asymptomatic. All morphologic abnormal ities resolved during 3-5 months follow-up.